Indian authorities have charged six men with murder, following the death of a student who was brutally gang-raped earlier this month on a bus in New Delhi.

Police say the men could face the death penalty if convicted.

The 23-year-old woman died early Saturday of severe organ failure at a hospital in Singapore. She underwent multiple surgeries in New Delhi before being flown to Singapore Thursday for special treatment.

News of her death prompted thousands of people to stage peaceful protests in the Indian capital, despite tight security to prevent mass demonstrations. The protesters demanded justice for the victim and safety for women.

New Delhi has been rocked by mass protests since the woman was attacked December 16.

Demonstrators also mourned her death with protests Saturday in Mumbai and Bangalore.

India Mourns Gang Rape Victim

Indian Prime Minister Manmohan Singh said he is "deeply saddened" by the woman's death. He said the emotions the case has generated are "perfectly understandable."

The woman's body was set to be flown back to India Saturday.

The woman is reported to have been traveling with a male companion on a charter bus in New Delhi when the six men on board beat them both with an iron rod. The woman was raped repeatedly. Reports say a rod was used in the rape, causing some of her internal injuries. She also suffered brain injuries. The woman and her friend were thrown from the moving vehicle.

The male friend survived the attack. Neither the woman nor her friend has been identified.

Many rapes in India go unreported. India's government has been criticized for being slow to understand the outrage that followed the incident, in a country where crimes against women are growing, and where police figures show that rape is among the fastest growing crimes.